Quantization errors in overlapped block digital filtering methods

In digital signal processing applications involving filtering long sequences, block filtering methods like overlapsave and overlap-add are widely used. Like all finite-precision applications, overlap-save and overlap-add methods are also affected by quantization errors. The goal of this paper is to calculate and make a quantitative comparison of the overall quantization noise resulting from the two methods in terms of power (variance) of the quantization noise. Multiple quantization noise sources are taken into consideration in the computation of the variances. The calculations reveal that the overlap-add approach is more prone to quantization noise compared to the overlap-save approach due to the addition of overlapping sections between overlap-add output blocks. Copyright © 2013 IARIA.